1. Field of the Invention
This invention relates to automotive radar systems, and more particularly to a radar system for sensing the presence of obstacles in a vehicle's "blind spots".
2. Description of Related Art
A continuing problem that presents itself to operators of automotive vehicles is the difficulty in seeing obstacles near the vehicle but in a location that is difficult to observe from the driver's seat. Such regions are commonly referred to as "blind spots". For example, the angles between 90.degree. and 170.degree. from the forward direction of a vehicle (i.e., to the right of the vehicle and slightly behind the operator thereof) is a common blind spot, particularly for large vehicles such as buses and tracks. This right-side blind spot is a source of numerous accidents when a driver makes a right-hand turn or a right lane change and does not see another vehicle in the blind spot. Another common blind spot is the rear of a vehicle when backing up.
The most common solution to the problem of blind spots has been to use mirrors to aid the operator of the vehicle in determining whether obstacles are present in a blind spot. Such mirrors have been made in a variety of shapes and mounted in various locations to provide the operator with the greatest ability to detect obstacles in particular blind spots. For example, it is common place today to see a concave mirror mounted to the right side of a vehicle aimed at the right-side blind spot. Mirrors provide the operator with some information regarding the presence of obstacles in certain of a vehicle's blind spots, but they are less useful at night and under adverse weather conditions. Hence, a more complete and satisfactory solution is still sought by many.
A known alternative to the use of mirrors to detect obstacles in a vehicle's blind spot is to mount a camera on the vehicle to provide the operator with a visual image of obstacles in the vehicle's blind spot. However, this solution is complex and expensive, requiring a video camera and video monitor. Further, a video monitor can present a complex image that must be interpreted by a driver, and such monitors can be distracting. Moreover, like mirrors, such camera systems are less useful at night and under adverse weather conditions.
Therefore, there is presently a need for a simple, and inexpensive solution to the problem of detecting hazardous obstacles in the blind spots of a vehicle. Such a solution should also be useful at night and under adverse weather conditions. The present invention provides such a solution.